'Mark Twain's Letters from Hawaii' Mark Twain spent four adventurous months in Hawaii back in 1866. Much has changed since then, but Twain's reports are still relevant and will acquaint you with the spirit of the islands even before you arrive.

'Oahu Revealed: The Ultimate Guide to Honolulu, Waikiki & Beyond' Andrew Doughty wrote a number of guidebooks, one for each Hawaiian island (at least those you can visit). If there is such a thing as a required purchase, this is it. The guide will be your bible during your stay, and is equally useful in preparation. You'll find out, for example, that Sea World isn't your only (or perhaps even your best) option if you want to swim with the dolphins. You'll find the best and cheapest places to eat, or the most expensive if that's what you're after. My wife and I planned a 7-day Hawaiian vacation, including our wedding and honeymoon, with the help of Oahu Revealed and honestly, I can't imagine how we would have managed without it. The other guidebooks include 'Maui Revealed: The Ultimate Guidebook (Maui the Big Island Revealed)', 'The Ultimate Kauai Guidebook: Kauai Revealed (Ultimate Kauai Guidebook)', and 'Hawaii The Big Island Revealed: The Ultimate Guidebook (Hawaii the Big Island Revealed)'.